#!/bin/sh

# run from directory where this script is
cd `dirname $0`
EXAMPLE_DIR=`pwd`

# Path for Wannier90
WAN_DIR=../../../wannier90-1.2

# check whether echo has the -e option
if test "`echo -e`" = "-e" ; then ECHO=echo ; else ECHO="echo -e" ; fi

$ECHO
$ECHO "$EXAMPLE_DIR : starting"
$ECHO
$ECHO "This example shows how to use pw2wannier90.x in conjunction with"
$ECHO "Wannier90 (http://www.wannier.org) to obtain maximally-localised"
$ECHO "Wannier functions (MLWFs) for the valence bands of diamond."
$ECHO "Wannier90 may be run in two modes, 'library' and 'standalone',"
$ECHO "and both of these are demonstrated."
$ECHO "for library mode pw2wannier90 has to be compile with -D__WANLIB flag,"
$ECHO "libwannier.a has to be linked. Uncomment related lines below."

# set the needed environment variables
. ../../../environment_variables

# required executables and pseudopotentials
BIN_LIST="pw.x pw2wannier90.x open_grid.x wannier90.x"
PSEUDO_LIST="C.pz-vbc.UPF"

$ECHO
$ECHO "  executables directory: $BIN_DIR"
$ECHO "  pseudo directory:      $PSEUDO_DIR"
$ECHO "  temporary directory:   $TMP_DIR"
$ECHO "  checking that needed directories and files exist...\c"

# check for directories
for DIR in "$BIN_DIR" "$PSEUDO_DIR" ; do
    if test ! -d $DIR ; then
        $ECHO
        $ECHO "ERROR: $DIR not existent or not a directory"
        $ECHO "Aborting"
        exit 1
    fi
done
for DIR in "$TMP_DIR" "$EXAMPLE_DIR/results" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results

# check for executables
for FILE in $BIN_LIST ; do
    if test ! -x $BIN_DIR/$FILE ; then
        $ECHO
        $ECHO "ERROR: $BIN_DIR/$FILE not existent or not executable"
        $ECHO "Aborting"
        exit 1
    fi
done

# check for pseudopotentials
for FILE in $PSEUDO_LIST ; do
    if test ! -r $PSEUDO_DIR/$FILE ; then
       $ECHO
       $ECHO "Downloading $FILE to $PSEUDO_DIR...\c"
            $WGET $PSEUDO_DIR/$FILE $NETWORK_PSEUDO/$FILE 2> /dev/null
    fi
    if test $? != 0; then
        $ECHO
        $ECHO "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
PW_COMMAND="$PARA_PREFIX $BIN_DIR/pw.x $PARA_POSTFIX"
WAN_COMMAND="$BIN_DIR/wannier90.x"
PW2WAN_COMMAND="$PARA_PREFIX $BIN_DIR/pw2wannier90.x $PARA_POSTFIX"
OG_COMMAND="$PARA_PREFIX $BIN_DIR/open_grid.x $PARA_POSTFIX"
$ECHO
$ECHO "  running pw.x as          : $PW_COMMAND"
$ECHO "  running wannier90.x as   : $WAN_COMMAND"
$ECHO "  running pw2wannier90.x as: $PW2WAN_COMMAND"
$ECHO "  running open_grid.x as:    $OG_COMMAND"
$ECHO

# self-consistent calculation for diamond
cat > diamond.scf.in << EOF
 &control
    calculation = 'scf'
    restart_mode='from_scratch',
    prefix='di',
    pseudo_dir='$PSEUDO_DIR',
    outdir='$TMP_DIR'
 /
 &system
    ibrav=  2, celldm(1) =6.1, nat=  2, ntyp= 1,
    ecutwfc =40.0,
 /
 &electrons
    diagonalization='david'
    mixing_mode = 'plain'
    mixing_beta = 0.7
    conv_thr =  1.0d-13
 /
ATOMIC_SPECIES
 C  12.0  C.pz-vbc.UPF
ATOMIC_POSITIONS {crystal}
C  -0.25 -0.25 -0.25
C   0.0  0.0  0.0
K_POINTS {automatic}
  4  4  4   0 0 0
EOF
$ECHO "  running the scf calculation for diamond...\c"
$PW_COMMAND < diamond.scf.in > diamond.scf.out
$ECHO " done"

# non-self-consistent calculation for diamond
#cat > diamond.nscf.in << EOF
# &control
#    calculation='nscf'
#    pseudo_dir='$PSEUDO_DIR',
#    outdir='$TMP_DIR',
#    prefix='di'
# /
# &system
#    ibrav=  2, celldm(1) =6.1, nat=  2, ntyp= 1,
#    ecutwfc =40.0, nbnd = 4,
# /
# &electrons
#    conv_thr =  1.0d-11
# /
#ATOMIC_SPECIES
# C  12.0  C.pz-vbc.UPF
#ATOMIC_POSITIONS {crystal}
#C -0.25 -0.25 -0.25
#C  0.0  0.0  0.0
#K_POINTS {crystal}
# 64
#0.0000  0.0000   0.0000   0.0156250
#0.0000  0.2500   0.0000   0.0156250
#0.0000  0.5000   0.0000   0.0156250
#0.0000  0.7500   0.0000   0.0156250
#0.2500  0.0000   0.0000   0.0156250
#0.2500  0.2500   0.0000   0.0156250
#0.2500  0.5000   0.0000   0.0156250
#0.2500  0.7500   0.0000   0.0156250
#0.5000  0.0000   0.0000   0.0156250
#0.5000  0.2500   0.0000   0.0156250
#0.5000  0.5000   0.0000   0.0156250
#0.5000  0.7500   0.0000   0.0156250
#0.7500  0.0000   0.0000   0.0156250
#0.7500  0.2500   0.0000   0.0156250
#0.7500  0.5000   0.0000   0.0156250
#0.7500  0.7500   0.0000   0.0156250
#0.0000  0.0000   0.2500   0.0156250
#0.0000  0.2500   0.2500   0.0156250
#0.0000  0.5000   0.2500   0.0156250
#0.0000  0.7500   0.2500   0.0156250
#0.2500  0.0000   0.2500   0.0156250
#0.2500  0.2500   0.2500   0.0156250
#0.2500  0.5000   0.2500   0.0156250
#0.2500  0.7500   0.2500   0.0156250
#0.5000  0.0000   0.2500   0.0156250
#0.5000  0.2500   0.2500   0.0156250
#0.5000  0.5000   0.2500   0.0156250
#0.5000  0.7500   0.2500   0.0156250
#0.7500  0.0000   0.2500   0.0156250
#0.7500  0.2500   0.2500   0.0156250
#0.7500  0.5000   0.2500   0.0156250
#0.7500  0.7500   0.2500   0.0156250
#0.0000  0.0000   0.5000   0.0156250
#0.0000  0.2500   0.5000   0.0156250
#0.0000  0.5000   0.5000   0.0156250
#0.0000  0.7500   0.5000   0.0156250
#0.2500  0.0000   0.5000   0.0156250
#0.2500  0.2500   0.5000   0.0156250
#0.2500  0.5000   0.5000   0.0156250
#0.2500  0.7500   0.5000   0.0156250
#0.5000  0.0000   0.5000   0.0156250
#0.5000  0.2500   0.5000   0.0156250
#0.5000  0.5000   0.5000   0.0156250
#0.5000  0.7500   0.5000   0.0156250
#0.7500  0.0000   0.5000   0.0156250
#0.7500  0.2500   0.5000   0.0156250
#0.7500  0.5000   0.5000   0.0156250
#0.7500  0.7500   0.5000   0.0156250
#0.0000  0.0000   0.7500   0.0156250
#0.0000  0.2500   0.7500   0.0156250
#0.0000  0.5000   0.7500   0.0156250
#0.0000  0.7500   0.7500   0.0156250
#0.2500  0.0000   0.7500   0.0156250
#0.2500  0.2500   0.7500   0.0156250
#0.2500  0.5000   0.7500   0.0156250
#0.2500  0.7500   0.7500   0.0156250
#0.5000  0.0000   0.7500   0.0156250
#0.5000  0.2500   0.7500   0.0156250
#0.5000  0.5000   0.7500   0.0156250
#0.5000  0.7500   0.7500   0.0156250
#0.7500  0.0000   0.7500   0.0156250
#0.7500  0.2500   0.7500   0.0156250
#0.7500  0.5000   0.7500   0.0156250
#0.7500  0.7500   0.7500   0.0156250
#EOF
#$ECHO "  running the nscf calculation for diamond...\c"
#$PW_COMMAND < diamond.nscf.in > diamond.nscf.out
#$ECHO " done"


# run pw2wannier90 to get overlap matrices
cat > diamond.openg.sa.in << EOF
&inputpp
   outdir = '$TMP_DIR/'
   prefix = 'di'
/
EOF
$ECHO "  running open_grid for diamond...\c"
$OG_COMMAND < diamond.openg.sa.in > diamond.openg.sa.out
$ECHO " done"

$ECHO "  getting list of k-points from open_grid output...\c"
grep -A64 List diamond.openg.sa.out|grep -v List > k_points.txt


# Wannier90 to get nnkp
cat > diamond.win << EOF
num_wann        =  4
num_iter        = 20

begin atoms_frac
C   -0.2500  -0.250    -0.25000
C    0.00000   0.0000     0.000000
end atoms_frac

begin projections
f=0.0,0.0,0.0:s
f=0.0,0.0,0.5:s
f=0.0,0.5,0.0:s
f=0.5,0.0,0.0:s
end projections

#begin unit_cell_cart
#-1.613990   0.000000   1.613990
# 0.000000   1.613990   1.613990
#-1.613990   1.613990   0.000000
#end unit_cell_cart

begin unit_cell_cart
bohr
-3.050   0.000   3.050
 0.000   3.050   3.050
-3.050   3.050   0.000
end_unit_cell_cart

mp_grid : 4 4 4

begin kpoints
$(cat k_points.txt)
end kpoints
EOF

# STANDALONE MODE
$ECHO
$ECHO "  <== Stand-alone Mode ==>\c"
$ECHO

mv diamond.win diamond.sa.win

# run wannier90 to get nnkp file
$ECHO "  running wannier90 -pp for diamond...\c"
$WAN_COMMAND -pp diamond.sa
$ECHO " done"

# run pw2wannier90 to get overlap matrices
cat > diamond.pw2wan.sa.in << EOF
&inputpp
   outdir = '$TMP_DIR/'
   prefix = 'di_open'
   seedname = 'diamond.sa'
   spin_component = 'none'
   write_mmn = .true.
   write_amn = .true.
   write_unk = .false.
   wan_mode = 'standalone'
/
EOF
$ECHO "  running pw2wannier90 in stand-alone mode for diamond...\c"
$PW2WAN_COMMAND < diamond.pw2wan.sa.in > diamond.pw2wan.sa.out
$ECHO " done"

# clean TMP_DIR
#$ECHO "  cleaning $TMP_DIR...\c"
#rm -rf $TMP_DIR/pwscf*
#$ECHO " done"

# run Wannier90 to obtain MLWFs
$ECHO "  running wannier90 for diamond...\c"
$WAN_COMMAND diamond.sa
$ECHO " done"

#########################################################
# LIBRARY MODE
########################################################
#$ECHO
#$ECHO "  <== Library Mode ==> \c"
#$ECHO

cp diamond.sa.win diamond.lib.win

# run pw2wannier90 to get overlap matrices
cat > diamond.pw2wan.lib.in << EOF
&inputpp
   outdir = '$TMP_DIR/'
   prefix = 'di'
   seedname = 'diamond.lib'
   spin_component = 'none'
   write_mmn = .true.
   write_amn = .true.
   write_unk = .false.
   wan_mode = 'library'
/
EOF
#$ECHO "  running pw2wannier90 in library mode for diamond...\c"
#$PW2WAN_COMMAND < diamond.pw2wan.lib.in > diamond.pw2wan.lib.out
#$ECHO " done"

############################################################

#clean TMP_DIR
$ECHO
$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/di.*
$ECHO
$ECHO "$EXAMPLE_DIR : done"
$ECHO
